This is a revised renewal of the Training Program in Signaling in Tissue Injury &Repair. Trainees recruited into the program undergo an intense training in the basic science aspects of tissue repair research utilizing laboratories at Virginia Commonwealth University. It is intended that during the two year experience, trainees will be exposed to the following areas of tissue repair biology: 1) the biology and phenotypic regulation of mesenchymal cells in development and repair;2) the protein and molecular biology of and regulation of expression of collagens, fibronectin and collagenases (matrix metalloproteinases);3) the role of cytokines in the regulation of matrix expression in mesenchymal cells;4) cytoskeletal proteins and signal transduction in mesenchymal cells;5) the role of inflammation, nitric oxide and inflammatory cells such as mast cells, macrophages and platelets in tissue repair;6) apoptosis and proto-oncogene expression;7) the physical properties of connective tissues and bioengineering;8) cellular and molecular signaling. Trainees will be encouraged to become familiar with the following techniques: 1) basic instrumentation including spectrophotometric and fluorescence techniques, HPLC, GLC, radioisotope counting and ultracentrifugation;2) radioimmunoassay;3) cell dispersion and isolation of subcellular organelles;4) cell culture techniques;5) isolation and purification and characterization of proteins (ion exchange chromatography, SDS/PAGE, Western blot analysis);6) Northern and Southern blot analysis and PCR;7) plasmid, phage and insert production, sub cloning and custom library production;and 8) small animal surgery. In addition to the laboratory training, each fellow is required to prepare and submit an individual NRSA as a learning experience to prepare them for their independent academic careers. Likewise, all fellows are required to submit proposals to other funding agencies such as the Plastic Surgery Educational Association, Jeffress Foundation and other sources in an effort to help support their research supply funds. Also, each fellow is taught how to prepare applications to the IRB and IACUC. Over the years this laboratory has trained approximately 30 fellows and many are productive scientists as academic physicians. This revised renewal proposal has been expanded and now includes a number of highly productive basic scientists with outstanding experience in the training of research fellows. Previously, many of these basic scientists were not engaged in the field of tissue repair and trauma, but now through this program they will become involved. In addition, this training program will seek applicants from Critical Care Medicine and Emergency Medicine as well as Surgery. The Program Director has made concerted efforts and will continue to strive to attract underrepresented minorities to apply to this unique training program.